import org.apache.flink.streaming.api.functions.source.RichParallelSourceFunction;

public class mySourceFun2 extends RichParallelSourceFunction<String> {

    @Override
    public void run(SourceContext<String> ctx) throws Exception {
        ctx.collect("wc");
        Thread.sleep(30000);
    }

    @Override
    public void cancel() {

    }
}
